(a) Field of the Invention
The present invention relates to an engine of a vehicle, more particularly, an intake duct system used for an engine of a vehicle.
(b) Description of the Related Art
An internal combustion engine receives air and fuel and burns them in a combustion chamber in order to produce mechanical power. Such an engine is provided with an intake system in order to supply fresh air into the combustion chamber. In order to supply fresh air so as to increase durability of the engine, an air cleaner that purifies the air is employed.
In order to improve the air purifying function of the intake system, it has been suggested to remove foreign particles by using rotation of air drawn into the engine in addition to employing the air cleaner. As an example, it is proposed to trap foreign particles that are forced toward an interior wall of the duct by inducing rotation of air passing through the duct of the intake system so as to apply a radial biasing force to foreign particles.
For such a function, a cyclone module for generating the rotation of air may be mounted inside the duct, and in this case, research has been undertaken in order to improve efficiency of the cyclone module. When turbulence is generated in the air that passes through the cyclone module, torque generated by the cyclone module for biasing the foreign particles toward the interior wall of the duct may be diminished. In this case, the foreign particle trapping function may be deteriorated since the particles are not applied with sufficient strength of centrifugal force.
Therefore, if the possible turbulence that may occur at a downstream side of the cyclone module may be prevented, performance of the cyclone module and the foreign particle eliminating function of the duct may be improved such that durability of an air cleaner and an engine may accordingly be improved.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.